1. Field of the Invention
The present invention concerns combination level and plumbs, and in particular combination level and plumbs for use in the building industry.
2. Discussion of the Related Art
Building brick walls can be difficult and time consuming, since accuracy can be of paramount importance. For example, when building any substantial structure, such as a house, it is important that the walls are vertical, and/or arranged exactly in accordance with the architect's plans. Failure to do this may result in the structure becoming unstable, eventually leading to degradation of the appearance and/or safety of the building.
Building walls vertically has traditionally been achieved by using a “plumb line,” which is a cord suspended from its upper end, which supports a weight attached to its lower end. Gravity causes the center of gravity of the weight to lie vertically beneath the point of suspension. The line of the cord, can therefore, be used as a guide against which the wall can be built.
In order to build a level wall, it is necessary for each layer or “course” of bricks to be level. This has traditionally been achieved by laying a spirit level on each course and tapping the bricks to bring them into alignment with the spirit level. Spirit levels are commonplace and require no further explanation.
Additional guides, commonly used by the builder include tri-squares and laser-sighting apparatus. There are a number of difficulties commonly encountered with any of the aforementioned items namely:
(a) they are independent of one another, and it is not therefore easy to make “spot checks” on the accuracy of the alignment of say, a single brick, or the “squareness” of a corner, without having to move or re-align two or more of aids;
(b) transporting or carrying all the necessary aids to accurately check, for example a comer, is difficult and inconvenient;
(c) certain guides, such as plumb lines, are not particularly portable, and can be influenced by external factors, winds for example, thereby degrading the accuracy of the build; and
(d) the aforementioned guides need to be re-aligned for each stage of a build, between each course of bricks for example.